const setContentString = (editor: Editor, body: HTMLElement, content: string, args: SetContentArgs): string => {
  let forcedRootBlockName, padd;

  // Padd empty content in Gecko and Safari. Commands will otherwise fail on the content
  // It will also be impossible to place the caret in the editor unless there is a BR element present
  if (content.length === 0 || /^\s+$/.test(content)) {
    padd = '<br data-mce-bogus="1">';

    // Todo: There is a lot more root elements that need special padding
    // so separate this and add all of them at some point.
    if (body.nodeName === 'TABLE') {
      content = '<tr><td>' + padd + '</td></tr>';
    } else if (/^(UL|OL)$/.test(body.nodeName)) {
      content = '<li>' + padd + '</li>';
    }

    forcedRootBlockName = Settings.getForcedRootBlock(editor);

    // Check if forcedRootBlock is configured and that the block is a valid child of the body
    if (forcedRootBlockName && editor.schema.isValidChild(body.nodeName.toLowerCase(), forcedRootBlockName.toLowerCase())) {
      content = padd;
      content = editor.dom.createHTML(forcedRootBlockName, editor.settings.forced_root_block_attrs, content);
    } else if (!content) {
      // We need to add a BR when forced_root_block is disabled on non IE browsers to place the caret
      content = '<br data-mce-bogus="1">';
    }

    editor.dom.setHTML(body, content);

    editor.fire('SetContent', args);
  } else {
    if (args.format !== 'raw') {
      content = Serializer({
        validate: editor.validate
      }, editor.schema).serialize(
        editor.parser.parse(content, { isRootContent: true, insert: true })
      );
    }

    args.content = Tools.trim(content);
    editor.dom.setHTML(body, args.content);

    if (!args.no_events) {
      editor.fire('SetContent', args);
    }
  }

  return args.content as string;
};

const renderBlock = (down: boolean, editor: Editor, table: HTMLElement, pos: CaretPosition) => {
  const forcedRootBlock = Settings.getForcedRootBlock(editor);

  if (forcedRootBlock) {
    editor.undoManager.transact(() => {
      const element = SugarElement.fromTag(forcedRootBlock);
      Attr.setAll(element, Settings.getForcedRootBlockAttrs(editor));
      Insert.append(element, SugarElement.fromTag('br'));

      if (down) {
        Insert.after(SugarElement.fromDom(table), element);
      } else {
        Insert.before(SugarElement.fromDom(table), element);
      }

      const rng = editor.dom.createRng();
      rng.setStart(element.dom(), 0);
      rng.setEnd(element.dom(), 0);
      moveToRange(editor, rng);
    });
  } else {
    moveToRange(editor, pos.toRange());
  }
};

const trimEmptyContents = (editor: Editor, html: string): string => {
  const blockName = Settings.getForcedRootBlock(editor);
  const emptyRegExp = new RegExp(`^(<${blockName}[^>]*>(&nbsp;|&#160;|\\s|\u00a0|<br \\/>|)<\\/${blockName}>[\r\n]*|<br \\/>[\r\n]*)$`);
  return html.replace(emptyRegExp, '');
};